Screen printing machines



E. ZIMMERMANN ET AL SCREEN PRINTING MACHINES Dec. 30, 1958 Filed Oct. 5,1955 NEH 2 Sheets-Sheet 1 l/ws/vroeg EHREN KHE'D INNERPIANN WERNERHENNING ATTORNEX 1958 EiZlMMERMANN ET AL 2,865,403

SCREEN PRINTING MACHINES Filed Oct. 5, 1955 2 Sheets-Sheet 2 EHRENFRIE'DZINNERMANN WERNER HENN I es ATTDKNEy' SCREEN PRlN TING MACHINESEhrenfried Zimmermann, Bunde-Sudlengern, and Werner H ennings,Bunde-Ennigloh, Germany, assignors to Bunder-Glas G. m. b. H.,Bunde-Westphalia, Germany, a German company Application October 5, 1955,Serial No. 538,694 Claims priority, application Germany June 6, 1955Claims. (Cl. 101--115) The invention relates to improvements in amachine for the printing of objects having a surface symmetrical aboutan axis as for example flasks, bottles, ampoules and the like.

It is known to provide these articles with labels according to theso-called screen printing process, wherein colour in a thick layer isapplied through a silk cloth or the like, which is permeable only atdetermined positions corresponding to the desired design, onto thearticle to be printed. It is known, by means of a special gearing byrods and cams or by a valve gear, to lift the spatula from the screen assoon as no workpiece is being brought to the screen, in order thereby toavoid an undesired penetration of colour. These devices are howevertroublesome and expensive. According to the invention the device is,instead, so constructed that the screen sags so loosely under thespatula that the engagement between spatula and screen is automaticallybroken, without using control devices, when a workpiece fails to arriveat the operative position.

The invention will now be illustrated by reference to tht drawingswherein;

Figure 1 is a side elevation of a screen printing device according tothe invention, partly in section, with a workpiece shown present in theoperative position,

Figure 2 is a similar view with no workpiece present in the operativeposition,

Figure 3 is a cross section partly in elevation of a printing deviceusing two groups of workpieces, and

Figures 4-6 are plan views of several cliches for three-, twoorsingle-colour printing.

Figure 1 shows a guide bed 1 for a screen printing stencil in the formof a rectangular frame 2 provided with silk screen 3, said stencil beingdisplaceable to and fro in the guide 4 in the direction of the arrows.

The trough-like space created by the frame 2 and screen 3 is partlyfilled with a viscous colour 5. A fixed spatula 6 projects into thecolour and serves as a counterbearing during the printing process.

Workpieces 7 are brought by means of a carrier pulley 8 into operativeposition opposite to the spatula 6 where they are supported on rollers 9and 10. When bringing the workpieces 7, for example, bottles or ampoulesinto operative position they are slightly lifted up over the roller 10and rest in the actual operative position between the two rollers 9 and10 in the manner shown in Figure l. The rollers 9 and 10 are for theirpart carried by a piston-like guide member 11, which through thepressure of spring 12 presses the workpiece over the rollers 9 and 10against the silk screen 3 and the spatula 6. If by means of a gear (notillustrated) the silk screen is moved from this position to the leftthen in this movement it carries with it the workpiece 7 which rolls onthe rollers 9 and 10 whereby colour is at the same time pressed throughthe openings in the silk screen which correspond to the desired patternand applied onto the workpiece 7. Thereafter the carrying device isbrought into the next position of rotation in nited States Patent 0 icewhich the next workpiece arrives at the operative position.

In order to prevent colour being pressed through the silk screen when noworkpiece arrives this screen is so loosely tensioned that in the.absence of workpiece (see Figure 2) the spatula 6 as a result of thesagging of the silk screen 3 possesses a suflicient separtion from thesilk screen. Only when a new workpiece arrives at the operative positionis the screen again pressed on, so that always only so much colour ispressed therethrough as is necessary for the printing. It is accordinglyquite unimportant for the neatness or clarity of the label to beproduced whether workpieces, or how many of them, fail to arrive duringthe continuous operation.

In order that the piston-like quide member 11 shall not force therollers 9 and 10 too high in the absence of a workpiece, so the movementupwards can be limited by means of a stop 13.

In Figure 3, 21 represents a carrier chain with channelshaped recesses22 in which the individual prismatic chain members, serve for receptionof the workpieces, which in the example illustrated in the drawingsconsist of two groups indicated respectively by clear and shaded circles23 and 24. All clear workpieces 23 are conducted to the printing cliche25 which cooperates with a spatula 26, all shaded workpieces 24 arrivingat the printing cliche 27 with its spatula 28. In order to effectprinting, lifting roller stands are provided in which one, 29, isarranged for the group 23 of workpieces and the other 30 is arranged forthe other group 24 of workpieces. The roller stands carry at the top apair of rollers 31 which here engage the workpiece from below and onlifting of the roller stand bring it into the zone of the printingcliches 25 or 27 and press it against the appropriate spatula 26 or 28.By means of the indicated silk screen 32, of the printing cliches 25 or27, which is led between the workpiece and the spatula the work- 'piecesare impelled or rolled, whereby the printing process is completed.Naturally the rollers 31 can also be driven by means of .a synchronoustransmission gear. The displacement of the workpieces is in this exampleequal to a double section of the prismatic chain 21.

Figures 4-6 show a few embodiments of clichs, more particularly forthree, two or single colour printing. The clich 33 for three-colourprinting is sub-divided into three separate sections by party walls 34,these sections each having their particular spatula 35, 36 or 37. Theclich 38 carries only one party wall and two spatulas 39 and 40 so thattwo colours can be printed. Clich 41 is undivided and has only onespatula 42.

With the clichs illustrated in Figures 4 and 5 the different colours cannaturally be applied only side by side.

If a workpiece is to be printed with several colours one over the other,then it must be led to several diflerentcoloured clichs disposed onebehind another. In the selection of a suitable displacement for thispurpose the device according to Figure 3 can for example be employed.

The clich according to Figure 6 can also be used for printing severalworkpieces side by side, if it also sags sufficiently laterally and theworkpieces are correspondingly small.

We claim:

1. A color 'screen printing machine for printing work pieces, comprisinghorizontally reciprocable frame, a saggable screen carried by saidframe, squeegee means mounted above and associated with said screenmember means in constant relative position with respect to said frame inthe vertical direction, means for conveying work pieces in proximity tothe said screen, the said squeegee means being disposed to engage thesaid screen when the said pieces are operably engaged with the saidscreen to permit the flow of color fluid therethrough and onto the saidworkpiece, and to become disengaged from the said saggable screen in theabsence of said work piece with no resulting color flow from the saidscreen a a result of ng t ret 2. A color screen printing machine forprinting work pieces according to claim 1 and wherein the said saggabloscreen comprises a plurality of saggable screen members disposed inside-by side relationship, and the said squee gee means comprises aplurality of squeegee members each mounted above and operable with asaggable screen member in response to the absence or presence of workiug pieces conveyed to the said screen members.

3. A color screen printing machine for printing wort, pieces accordingto claim 1 wherein the saidisaggablu screen comprises a plurality ofsaggable screen members sequentially disposed, and the said squeegeemeans comprises a plurality of squeegee members each mounted above andoperable with a saggable screen member in response tothe absence orpresence of working pieces conveyed to the said screen members, andmeans operable with said conveying means for sequentially positioningsaid work pieces in operable engagement with said sequentially disposedscreen.

4. A color screen printing machine for printing work pieces according toclaim 1 wherein the said saggable screen comprises a substantially widescreen member adapted to operably engage'at least one or more workpieces in side-by-side relationship, and the said squeegee meanscomprises a substantially Wide squeegee member mounted above andoperable with said screen member in response to the presence of saidwork pieces in side-byside relation.

5. A color screen printing machine for printing work pieces according toclaim 1 wherein the said saggablc screen comprises a plurality of spacedscreen members each adapted to transmit different colors, and the saidsqueegee means comprising a plurality of r-squeegees each mounted abovesaid screens and disposed to operably engage the said screens inresponse to the presence of working pieces and means for selectivelyconveying said pieces to selective screens to permit selective colorprinting of the said working pieces.

References Cited in-the file of this patent UNITED STATES PATENTS2,009,098 Smith et .al. July 23, 19.35 2,060,385 Shurley e t al. Nov.10, 1936 2,174,298 W'hisner Sept. 26, 1939 2,613,595 Weldon Gct. 14,1952 2,629,321 Gattuso 'Feb. 24, 1953

